Take b = 2.

b^(n-1) mod n = 1.

1747 is prime.

b^((n-1)/1747)-1 mod n = 3301997, which is a unit, inverse 3640192.

89 is prime.

b^((n-1)/89)-1 mod n = 4668116, which is a unit, inverse 797003.

(89 * 1747) divides n-1.

(89 * 1747)^2 > n.

n is prime by Pocklington's theorem.